Compact power running board

ABSTRACT

A compact deployable/retractable running board assembly for a motor vehicle including a running board, linkage coupled to the running board, and a motor assembly coupled to an actuator, the running board moveable between at least one stowed position and at least one deployed position. The linkage includes a drive arm connected to a pivot shaft within a housing at a location on the pivot shaft between two bushings that are coupled to the pivot shaft within the housing. The linkage also includes an idler arm connected to a pivot shaft within an idler housing. The actuator is operably coupled to the linkage to cause rotation of the linkage to move the running board between the at least one stowed position generally under the motor vehicle and at least one deployed position to provide a step surface for a user.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 15/481,637, filed Apr. 7, 2017, which is a continuation of U.S.patent application Ser. No. 14/807,070, filed Jul. 23, 2015, issued asU.S. Pat. No. 9,649,983, which claims the benefit of U.S. ProvisionalApplication No. 62/028,006, filed Jul. 23, 2014. The disclosures of theabove applications are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a compact structure for use in a powerrunning board system for automotive applications.

BACKGROUND OF THE INVENTION

Known power running boards have a large, high package size suitable forlarger vehicles such as pickup trucks. These boards are generallymoveable to gain access to passenger cabs and/or a cargo bed box.Parallel swing arms are typically connected on the outside of respectivehousings to pivot shaft ends, which increases the overall height of theassembly. To avoid high internal forces and stresses, this cantileverstructure also requires a larger housing, which increases the weight ofthe assembly.

Accordingly, there exists a need for a compact and lighter weightrunning board assembly for a motor vehicle. More particularly, thereexists a need for a lighter compact running board assembly adaptable foruse on smaller motor vehicles, such as sport utility vehicles (SUVs),that includes a running board movable between at least one stowedposition and at least one deployed position.

SUMMARY OF THE INVENTION

The present invention is directed to a compact running board assemblyfor a motor vehicle. The assembly is provided with a low height profile,which makes the assembly particularly adapted for motor vehicles withless ground clearance than conventional pickup trucks, such as sportutility vehicle and etc.

The running board assembly includes a housing assembly, an actuatorassembly, which is preferably a rotary actuator assembly disposed withinthe housing assembly, a linkage, a mounting bracket adapted forattachment of the running board assembly to the motor vehicle, a runningboard coupled to the linkage and movable relative to the mountingbracket between at least one stowed position generally locatedunderneath the motor vehicle and at least one deployed position, e.g.,motor vehicle compartment entry position, a motor assembly operablycoupled to the actuator for driving movement of the linkage andtherefore the running board, and an electronic control unitelectronically connected to the motor assembly and programmed toselectively supply voltage to said motor assembly and to turn off saidmotor assembly when said running board reaches said at least one stowedor at least one deployed positions.

A pivot shaft is located within a housing, and the linkage includes adrive arm connected to the pivot shaft within the housing at apredetermined location on the pivot shaft between two bushings that arecoupled to the pivot shaft within the housing. The bushings are spacedan operable predetermined distance apart from each other and with theswing arm at a predetermined location therebetween, which provides animproved balanced force condition since the bushing and housing reactionforces are significantly reduced. Another pivot shaft is located withinanother housing, and the linkage also includes an idler arm connected tothe pivot shaft within that housing. Two bushings are also coupled tothe pivot shaft within the housing with the idler arm coupledtherebetween on the pivot shaft. The actuator is operably coupled to thelinkage to cause rotation of the linkage to move the running boardbetween the at least one stowed position and at least one deployedposition. The attachment locations of the drive arm and idler arm withinthe respective housings between the at least two bushings, respectively,provides a compact, reduced height package for smaller clearancevehicles. The arrangement also allows for a smaller housing tosignificantly reduce the weight of the compact running board assembly.

According to another aspect of the invention, a running board assemblyis provided for a motor vehicle having a passenger cab and a box. Therunning board assembly includes a housing assembly, a linear actuatorassembly partly disposed within the housing assembly, a running boardoperably coupled to the linear actuator assembly and movable relative tothe housing assembly between a stowed position tucked underneath themotor vehicle, a cab entry position generally outwardly from the motorvehicle to support a user entering or exiting the passenger cab, and abox side step position disposed generally outwardly from the motorvehicle and rearward of the cab entry position to provide a user withside access to the box, and a motor operably coupled to the linearactuator assembly for driving the linear actuator assembly in opposingfirst and second directions to move the running board between the stowedposition, the cab entry position, and the box side step position. Thelinear actuator assembly converts rotary input to linear motion.

According to another aspect of the invention, a running board assemblyfor a motor vehicle having a passenger cab and a box includes a housingassembly, a linear actuator assembly partly disposed within the housingassembly, and a running board operably coupled to the linear actuatorassembly and movable relative to the housing assembly between a stowedposition tucked underneath the motor vehicle, a cab entry positiongenerally outwardly from the motor vehicle to support a user entering orexiting the passenger cab, and a box side step position disposedgenerally outwardly from the motor vehicle and rearward of the cab entryposition to provide a user with side access to the box. The runningboard assembly also includes a drive arm fixedly secured to the runningboard and operably coupled to the linear actuator assembly. The drivearm further includes at least a first and second link for moving thedrive arm as the linear actuator assembly is actuated. The running boardassembly further includes a motor operably coupled to the linearactuator assembly for driving the drive arm to pivotally move therunning board between the stowed position, the cab entry position, andthe box step side position, and an electronic control unit operablycoupled to the motor and programmed to turn off the motor after apredetermined number of armature revolutions to stop the running boardin the cab entry position.

In accordance with another embodiment, the drive arm also includes afirst stop engageable with the running board to stop the running boardin the stowed position and a second stop engageable with the runningboard to stop the running board in the box step side position.

According to yet another aspect of the invention, a running boardassembly for a motor vehicle includes a mounting bracket adapted forattachment to the motor vehicle, a running board movable relative to themounting bracket between a stowed position tucked underneath the motorvehicle, a cab entry position disposed generally outwardly from themotor vehicle, and a box side step position disposed generally outwardlyfrom the motor vehicle and generally rearward to the cab entry position,a motor operably coupled to the running board for driving movementthereof, and an electronic control unit electronically connected to themotor and programmed to turn off said motor when said running boardreaches said cab entry position. The running board assembly alsoincludes a housing assembly including a worm member operably coupled tothe motor. The housing assembly includes a zero backlash worm selflocking member, to eliminate backlash of the running board when therunning board is in the cab entry position, having a worm gear fixedlymounted on an end of a ball screw and a ball nut mounted along the ballscrew for movement relative thereto.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a perspective view of a compact power running board assembly,depicted in a deployed position, according to an embodiment of thepresent invention;

FIG. 2 is a perspective view of the compact power running board assemblyof FIG. 1, depicted in a stowed position;

FIG. 3 is a cross sectional view of a drive arm swing mechanism of thecompact power running board assembly including a rotary actuator, andcoupled to the running board and to an electronic control unit;

FIG. 4 is a cross sectional view of an idler arm of the compact powerrunning board assembly coupled to the running board and to a pivot shaftwithin a housing;

FIG. 5 is a bottom perspective view of the compact power running boardof FIG. 1;

FIG. 6 is an enlarged perspective view of a mechanical stop against therunning board in a deployed position;

FIG. 7 is an enlarged perspective view of a mechanical stop against therunning board in a stowed position;

FIG. 8 is an enlarged perspective view of the housing with an openingfor receiving the drive arm, mounting bracket for connecting to a motorvehicle, and a motor assembly coupled to the housing;

FIG. 9 is a perspective view of the compact power running board assemblyin a deployed position shown in an environment of use mounted to a motorvehicle;

FIG. 10 is a perspective view of the compact power running boardassembly in a stowed position shown in an environment of use mounted tothe motor vehicle;

FIG. 11 is a perspective view of a compact power running board assemblywith a linear actuator assembly, depicted in a deployed position,according to an embodiment of the present invention;

FIG. 12 is a rear elevation of FIG. 12;

FIG. 13 is a perspective view of a known running board assemblyincluding a running board;

FIG. 14 is a sectional view taken through a housing of FIG. 14 and acantilever arm connected to a pivot shaft end outside of the housing;

FIG. 15 is a perspective view of one embodiment of a running boardassembly including a running board;

FIG. 16 is a side view of a motor vehicle including the running board ina stowed position;

FIG. 17 is a side view of the motor vehicle including the running boardin a cab entry position;

FIG. 18 is a side view of the motor vehicle including the running boardin a box side step position;

FIG. 19 is a perspective view of a housing assembly with a linearactuator assembly, a drive arm, and a motor assembly of the runningboard assembly;

FIG. 20 is an exploded view of the linear actuator assembly of therunning board assembly;

FIG. 21 is a perspective view of the running board assembly including anelectronic control unit;

FIG. 22 is a fragmentary rear perspective view of the motor vehicleincluding an end cap switch and a body-mounted switch for activatingmovement of the running board into and out of the box side stepposition;

FIG. 23 is a perspective view of a linear actuator assembly connected tothe running board, in accordance with another aspect of the presentinvention;

FIG. 24 is a perspective view of a linear actuator assembly with a geardrive arrangement, in accordance with another aspect of the presentinvention; and

FIG. 25 is a perspective view of a linear actuator assembly with a beltdrive arrangement, in accordance with another aspect of the presentinvention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The following description of the preferred embodiment(s) is merelyexemplary in nature and is in no way intended to limit the invention,its application, or uses.

Referring to FIGS. 1-12 generally, there is provided a compact powerrunning board assembly, shown generally at 100, according to the presentinvention, including at least one drive swing arm mechanism, showngenerally at 102, and at least one idler swing arm mechanism, showngenerally at 104. A running board 106 is connected to a first swing arm108 (or “pivot linkage” or “drive arm”) of the drive swing arm mechanism102 and to a second swing arm 110 of the idler swing arm mechanism 104at outboard pivot sub-assemblies indicated generally at 112 (“pivotsub-assemblies”).

The pivot sub-assemblies 112,112 are arranged generally vertically inthe motor vehicle installed position. Alternative arrangements arecontemplated depending on the application without departure from thescope of the present invention. Preferably, the bottom of the pivotsub-assemblies 112 are secured to a bottom surface of the running board106 by at least one mounting bracket 114 with at least one fastener 116.Preferably, the top of the pivot sub-assemblies 112 are secured to achannel 118 formed in the running board 106. However, any other mountingstructures suitable for securing to the running board 106 arecontemplated depending on the application without departure from thescope of the present invention.

The first and second swing arms 108,110 are generally parallel to oneanother and move the running board 106 from at least one stowed positionto at least one deployed position. The running board 106 includes a stepsurface 120, preferably, a top treaded surface, for use in the at leastone deployed position.

At least one compact power running board 100 is connected to the motorvehicle in at least one predetermined location to at least one vehiclecomponent, e.g., connected to metal framing, connected to motor vehicleframe adjacent to a rocker panel, adjacent a bumper, adjacent a bodypanel, connected to any other predetermined metal or compositecomponent(s), etc. Preferably, the running board is moved, mostpreferably swung, generally horizontally from the stowed position underthe vehicle in a generally outward direction to at least one deployedposition that provides a user step for accessing a front and/or reardriver/passenger compartment of a motor vehicle, such as a sport utilityvehicle. Most preferably, the swing arms 108,110 form a linkage,indicated generally at 111, that rotates the running board 106horizontally and outward in unison to the at least one deployedposition.

When in the stowed position, the running board 106 is generally at leastpartially positioned under the vehicle, typically, substantially underthe vehicle, preferably, with the outboard edge 121 of the running board106 generally adjacent and below an outer vehicle component 122 (e.g., arocker panel, body panel or any other predetermined panel or componentof any kind of the motor vehicle). FIG. 9 illustrates an exemplarydeployed position. FIG. 10 illustrates an exemplary stowed position.

The drive swing arm mechanism 102 also includes at least one housing 124and an actuator assembly shown generally at 126. Preferably, theactuator assembly is a rotary assembly arrangement. Alternativeactuators are contemplated depending on the application withoutdeparture from the scope of the present invention, including, but notlimited to, linear actuators, pneumatic, hydraulic, ball screw/nutlinear actuator, gear driven linear actuator, belt driven linearactuator, and etc.

The housing 124 has at least one opening 128 that receives the firstswing arm 108. An inboard pivot shaft 130 (“pivot shaft”) is locatedwithin the housing 124, and first and second bushing bearings 132 and134 are operably coupled to the pivot shaft 130 and located within thehousing 124. The pivot shaft 130 and bushings 132, 134 are completelycontained within the housing 124 and do not extend outside of thehousing 124. The first swing arm 108, however, extends through thehousing opening 128 and is operably connected to the pivot shaft 130within the housing 124 at a location along the pivot shaft 130 betweenthe first and second bushings 132, 134. The opening 128 in the housing124 is sized to also allow the first swing arm 108 to rotate between thestowed position and the at least one deployed position withoutinterference by the housing 124 structure.

The pivot shaft 130 is of a predetermined length and the first andsecond bushings 132, 134 are spaced a predetermined effective distanceapart on the pivot shaft 130, depending on the application, for allowinga better and balanced force condition. With the bushing span distancebeing longer, there is a reduction in the busing and housing reactionforces. The first and second bushings' 132, 134 reaction forces aresignificantly reduced, in accordance with the present invention, e.g.,at least about 2 times less. By way of non-limiting example, with a 1000N directional force applied to the pivot shaft 130 generally where thefirst swing arm 108 is connected (at a predetermined location betweenthe first and second bushings 132, 134), about a 500 N reaction force isapplied to the first bushing 132 and about a 500 N reaction force isapplied to the second bushing 134.

The pivot bushing arrangement is a significant advantage over knownarrangements since it provides a lighter weight, lower profile assemblywith an improved balanced force condition providing a robust yet morecompact design for motor vehicles such as SUVs.

At least one thrust bearing 136 is provided on the pivot shaft 130between the first bushing 132 and the first swing arm 108. The thrustbearing 136 functions as a spacer. Additionally, directional force fromthe swing arm 108 is transferred to the thrust bearing 136 where it isthen transferred on to the first bushing 132. Preferably, the thrustbearing 136 is a bronze annulet, however, alternative suitable materialsare contemplated without departure from the scope of the presentinvention.

A gap 138 of predetermined width is provided between the pivot arm 108and the housing 124, longitudinally and/or horizontally disposed.Preferably, the gap is at least 0.2 mm wide, most preferably, about 0.5mm. At least one first seal 140 and at least one second seal 142 areprovided to protect against moisture within the housing 124. Mostpreferably, the first and second seals 140, 142 are oil seals. The firstseal 140 is located below the swing arm 108 on the outside of the thrustbearing 136 to protect against water that entered from the opening 128in the housing 124. The second seal 142 is located above the swing arm108 between the housing 124 and a hub 144. Since there is a gap 138 tothe pivot arm 130 but there are the first and second seals 140, 142provided, the moisture that entered the housing 124 through the opening128 eventually comes back out of the opening 128.

The actuator assembly 126 is preferably a rotary actuator including aworm gear 146 in mesh with a worm wheel 148 (e.g., peripheral teeth ofthe worm wheel 148 in operably meshing engagement with spiral threads ofthe worm gear 146), and a motor assembly, shown generally at 150,operably coupled to the worm gear 146. The meshing engagement can alsoprevent back driving of the running board when deployed. The hub 144 ispart of the worm wheel 148 and encircles the pivot shaft 130. At leastone key member 152 is provided that operably keys the first swing arm108 and pivot shaft 130 to the worm wheel 148. The key member 152 ispreferably steel. Alternatively, the key member 152 keys to the swingarm 108 and worm wheel 148.

The motor assembly 150 is controlled by an electronic control unit(ECU), shown generally at 154, to effect movement of the running board106 between the stowed position and the at least one deployed position.Under predetermined conditions the ECU 154 supplies voltage to the motorassembly 150 to cause rotational movement of the motor 150 device,preferably, to a planetary gear device indicated generally at 166.Rotation of the worm gear 146 caused by the motor 150 drives rotation ofthe in-meshed worm wheel 148 which in turn, since the worm wheel 148 andfirst swing arm 108 are keyed in to the pivot shaft 130 by the key 152,causes rotation of the pivot shaft 130 which drives pivotal movement ofthe first swing arm 108. Thus, rotational movement is converted into thepivotal movement that causes the linkage to swing the running board 106outward from the stowed position to the at least first deployedposition.

The arrangement of the present invention also allows the worm wheel 148,in particular, the hub 144, to be shorter, which further decreasesmaterial and the size of the housing 124.

At least one over current sensor 156 is operably coupled to the motor150 that detects current spikes and causes the actuator assembly 126 toreact to certain conditions (e.g., senses the running board 106contacting mechanical stop(s) on the swing arm(s), contacting anobstruction, object detection, etc). By non-limiting example, if therunning board 106 hits something while deploying or otherwise encountersresistance to the movement, the sensor 156 senses the current spike foroverride and the ECU 154 stops the application of voltage to the motor150 and the actuator 126 will stop deploying or will stop retracting therunning board 106 further while the condition exists.

At least one dome spring washer 158 is operably coupled to the pivotshaft 130 adjacent a cover 160 of the housing 124. The spring washerkeeps an axial force, i.e., up and down, between the worm wheel 148 andthe worm gear 146.

At least one o-ring 162 is provided adjacent the pivot shaft 130 toprevent water from the key from entering the gearing. Preferably, theo-ring is a rubber o-ring coupled to the pivot shaft 130.

The housing 124 is preferably a gear housing and provides a mount to themotor vehicle. At least one mounting bracket member, shown generally at168, is provided on the housing 124, preferably, integrally formed withthe housing 124. The mounting bracket member 168 includes at least aninboard mounting bracket 170 and outboard mounting bracket 172. Theinboard mounting bracket 170 is operably connected to the motor vehicle174 at a predetermined location further underneath the vehicle with atleast one fastener. The outboard mounting bracket 172 is operablyconnected to the motor vehicle 174 at a predetermined location furtheroutboard from the inboard mounting bracket 170 with at least onefastener, such as to an outermost channel under the motor vehicle 174.The mounting brackets 170, 172 are an operable predetermined length forattachment to an outboard channel and another motor vehicle component. Astanding force applied to the step surface 120 is transferred to the twomounting brackets 170, 172 and mounting brackets on the idler swing armmechanism 104.

The compact power running board assembly 100 also includes at least onemechanical stop, shown generally at 176. The mechanical stop 176 isoperably connected on the first swing arm 108 or the second swing arm110, most preferably, fixedly connected on the first swing arm 108, andis operable to cooperate with the over current sensor 156 operablycoupled to the motor assembly 150. The mechanical stop 176 includes amounting bracket 178 with at least one pair of stops shown generally at180. Preferably, the mounting bracket 178 is substantially L-shaped andconnected to the swing arm by at least one fastener 182.

The pair of stops 180 create interference with the running board 106 andthe over current sensor 156 detects the interference. A first bumper 184on a first half 186 of the mounting bracket 178 contacts a rear surface188 of the running board 106 when the swing arm 108 is extended to thedeployed position. A second bumper 190 on a second half 192 of themounting bracket 178 contacts the rear surface 188 of the running board106 when the swing arm 108 is retracted to the stowed position. Thelinkage rotates in one direction until the rear surface 188 of therunning board 106 contacts the first bumper 184 to stop further rotationof the first swing arm 108 when the running board 106 reaches thedeployed position, and the over current sensor/ECU 156/154 detects thecurrent spike generated from the contact with the running board 106 andturns the motor assembly 150 off. The linkage rotates in anotherdirection until the rear surface 188 of the running board 106 contactsthe second bumper 190 of the mechanical stop 176 to stop furtherrotation of the first swing arm 108 and running board 106 when therunning board 106 reaches the stowed position, and the over currentsensor/ECU 156/154 detects the current spike generated from the contactwith the running board 106 and turns the motor assembly 150 off. Thefirst and second bumpers 184, 190 are urethane, rubber or other suitablematerial to prevent scratching the running board 106 and for sounddeafening.

The idler swing arm mechanism 104 also includes a housing 194 (or “idlerhousing”) with at least one opening 196 that receives the second swingarm 110. An inboard pivot shaft 198 (or “idler pivot shaft”) is locatedwithin the housing 194, and first and second bushing bearings 200 and202 (or “first and second idler bushings”) are operably coupled to thepivot shaft 196 and located within the housing 194. The pivot shaft 196and bushings 200,202 are completely contained within the housing 194 anddo not extend outside of the housing 194. The second swing arm 110,however, extends through the housing opening 196 and is operablyconnected to the pivot shaft 198 within the housing 194 at a locationalong the pivot shaft 197 between the first and second bushings 200,202.The pivot shaft 198 is of a predetermined length and the first andsecond bushings 200,202 are spaced a predetermined effective distanceapart on the pivot shaft 198, depending on the application, for allowinga better and balanced force condition. The opening 196 in the housing194 is sized to also allow the second swing arm 110 to rotate betweenthe stowed position and the at least one deployed position withoutinterference by the housing 194 structure.

At least one thrust bearing 204 is operably coupled to the pivot shaft194 between the first bushing 200 and the second swing arm 110. Thethrust bearing 204 functions as a spacer. Additionally, directionalforce from the swing arm 110 is transferred to the thrust bearing 204where it is then transferred on to the first bushing 200.

At least one second thrust bearing 206 is operably coupled to the pivotshaft 194 between the second bushing 202 and the second swing arm 110.The second thrust bearing 206 functions as a spacer. Additionally,directional force from the swing arm 110 is also transferred to thesecond thrust bearing 206 where it is then transferred on to the secondbushing 202.

At least one first seal 208 and at least one second seal 210 areprovided to protect against moisture within the housing 194. Mostpreferably, the first and second seals 208,210 are oil seals. The firstseal 208 is located below the swing arm 110 on the outside of the thrustbearing 204 to protect against water that entered from the opening 196in the housing 194. The second seal 210 is located above the swing arm110 on the outside of the second thrust bearing 206 to protect againstwater that entered from the opening 196 in the housing 194. Any moisturethat entered the housing 194 through the opening 196 can eventually comeback out of the opening 196.

The housing 194 also provides a mount to the motor vehicle. At least onemounting bracket member, shown generally at 212, is provided on thehousing 194, preferably, integrally formed with the housing 194. Themounting bracket member 212 includes at least an inboard mountingbracket 214 and outboard mounting bracket 216. The inboard mountingbracket 212 is operably connected to the motor vehicle 174 at apredetermined location further underneath the vehicle with at least onefastener. The outboard mounting bracket 214 is operably connected to themotor vehicle 174 at a predetermined location further outboard from theinboard mounting bracket 212 with at least one fastener, such as to theoutermost channel under the motor vehicle 174. The mounting brackets212,214 are an operable predetermined length for attachment to anoutboard channel and another motor vehicle component. A standing forceapplied to the step surface 120 is transferred to the two mountingbrackets 212,214 and mounting brackets 170, 172 on the drive swing armmechanism 102.

The electronic control unit 154 electronically controls the motorassembly 150 to effect movement of the running board 106 between thestowed position and at least one deployed position. The electroniccontrol unit 154 is mounted within the motor vehicle 174 at a locationremote from the housing assembly 124 or operably coupled to theassembly. The electronic control unit 154 is electrically connected tothe motor assembly 150, to a wiring harness of the motor vehicle, and toa switch member 218, e.g., incorporated into a door of the motorvehicle. The switch member 218 can be a door-actuated switch member thatis part of the motor vehicle and is controlled in a conventional mannerby the door. The wiring harness supplies the electrical power from thevehicle electrical system to the ECU 154 of the running board assembly100 through electrical wire members 220. The structure and operation ofa conventional switch member which is operationally interconnected tothe vehicle door is well known. It is understood by one skilled in theart that such switch members are toggled by the opening or the closingof the vehicle door associated therewith to open and close an electricalcircuit. Wire members 222 provide electrical connection between the ECU154 and the motor assembly 150 so that the ECU 154 can supply electricalpower from the vehicle electrical system to the motor assembly 154 toeffect the bi-directional operation thereof. The switch member 218 isoperably connected to the ECU 154 by wire members or by a wirelessconnection, e.g., wire members 224 provide electrical communicationbetween the ECU 154 and the switch member 218.

In one embodiment, the switch member 218 is a door ajar switch in a doorlatch. The motor assembly 150 is energized to move the running board 106from the stowed position to a deployed position upon receiving a signalfrom the door ajar switch indicating that the vehicle door has beenopened. The motor assembly 22 is energized to return the running board106 to the stowed position upon receiving a signal from the door ajarswitch indicating that the vehicle door has been closed. Alternatively,or additionally, a motor vehicle body mounted switch 226, that isaccessible by a user to activate the running board 106 when desired,initiates movement of the running board 106. The body-mounted switch 226is operably connected to the ECU 154 by wire members or by a wirelessconnection. Alternatively, or additionally, an end cap switch 228 or keyfob is provided to initiate movement of the running board 106. Therunning board 106 may be hand-operated, or foot-operated if hands-freeoperation of the running board 106 is desired, using the switches. Uponactivation of one of the switches 224, 226, 226 or the key fob, a signalis sent to the ECU 154 and the ECU 154 sends appropriate voltage to themotor assembly 150.

The height of the compact power running board assembly 100 isparticularly suitable for motor vehicles with less ground clearance,such as sport utility vehicles, while maximizing the ground clearancethat is available to help prevent assembly 100 contact against motorvehicle driving surfaces or objects thereon.

The running board 106 is preferably an extruded aluminum. Othermaterials are contemplated depending on the application withoutdeparture from the scope of the present invention. The first and secondswing arms 108,110 are preferably cast aluminum. Other materials arecontemplated depending on the application without departure from thescope of the present invention. The housing is preferably cast aluminum.Other materials are contemplated depending on the application withoutdeparture from the scope of the present invention.

It is understood that, alternatively, the assembly 100 is adapted tohave the drive swing arm mechanism 102 and idler swing arm mechanism 104locations switched, as in the drive swing arm mechanism 102 may belocated where the idler swing arm mechanism 104 is illustrated in thefigures and the idler swing arm mechanism 104 would then be locatedwhere the drive swing arm mechanism 102 is illustrated in the figures.

In accordance with an embodiment of the present invention, a compactpower running board assembly is provided, shown generally at 300 inFIGS. 11-12, with linear actuation, wherein like numbers indicate likeparts to the compact power running board assembly 100. The compact powerrunning board assembly 300 includes at least one drive swing armmechanism, shown generally at 302, and at least one idler swing armmechanism 104. In this embodiment, a linear actuator assembly is added,as indicated generally at 303. The running board 106 is connected to afirst swing arm 308 of the drive swing arm mechanism 302 and to thesecond swing arm 110 of the idler swing arm mechanism 104 at the pivotsubassemblies 112,112. The assembly 300 is provided with the at leastone mechanical stop 176 and a motor assembly shown generally at 350 withat least one over current sensor 356 operably coupled to the motorassembly 350.

As described previously, the idler swing arm mechanism 104 includes ahousing 194 with inboard and outboard mounting brackets 214,216 toconnect to the motor vehicle 174, and the housing 194 has an opening 196to receive the second swing arm 110 into the housing 194, which swingarm 110 is operably coupled to the inboard pivot shaft 198 inside thehousing 196 at a predetermined location between the first and secondbushings 202,204 located within the housing. This arrangement provides acompact unit and a balanced force condition. Thrust bearings 204,206 fortransferring force are operably coupled to the pivot shaft 198 below andabove the swing arm 110, respectively, and first and second seals208,210 are operably coupled to the outside of the thrust bearings204,206 to protect against moisture. Preferably, the drive arm mechanism302 is identical thereto. Thus, most preferably, the gearing is notpresent in the housing of the drive swing arm mechanism 302, e.g., noworm gear 146 or worm wheel 148, and the housing and interior featuresof the drive swing arm mechanism 302 are substantially similar to theidler side in accordance with this embodiment.

The swing arms 308,110 form a linkage, indicated generally at 315, thatrotates the running board 106 generally horizontally between the stowedposition and the at least one deployed position until the board 106contacts the mechanical stop 176 and current spikes are detected,similarly as set forth previously. However, rather than rotaryactuation, the linear actuator assembly 303 moves the first swing arm308 between the stowed position and any predetermined deployedposition(s).

The linear actuator assembly 303 is operably connected to a third arm309 at a first pivot 311 and is operably connected to the first swingarm 308. Preferably, the other end of the third arm 309 is operablyconnected to the housing of the drive swing arm mechanism 302. Thelinear actuator assembly 303 includes the motor assembly 350 and acylinder or lead screw assembly, shown generally at 313. The motorassembly 350 is operably electrically connected to the ECU 154.

The motor assembly 350 generally includes a motor with gearboxreduction. Preferably, a planetary gear. Most preferably, a two-stageplanetary gear. The gearbox can be a planetary gear, worm gear, or othersuitable gear train.

The motor assembly 350 is illustrated outside and in-line with thecylinder or lead screw assembly 313. However, it is understood that theassembly 303 is adaptable for having an in-line or off-line motorassembly 350. In addition, it is understood that the assembly 303 isadaptable for having an in-line or off-line motor gear reduction box.The linear actuator assembly 303 uses a lead screw/spindle or screw-nut.The assembly 303 can use a pneumatic cylinder or hydraulic cylinder.Thus, the linear actuator assembly 303 generally includes either or acombination of the following: in-line or off-line motor; in-line oroff-line gear reduction box; gearbox that is planetary gear, worm gearor other gear train; uses lead screw/spindle or screw-nut; usespneumatic cylinder or hydraulic cylinder.

By way of non-limiting example, when a ball screw member rotates in afirst direction, this causes the first swing arm 308 to pivot outward tothe predetermined at least one deployed position. And when the ballscrew member rotates in a second direction, this causes the first swingarm 308 to pivot inward toward the motor vehicle to the stowed position.

Referring now to FIGS. 13-14, there is illustrated a known power runningboard assembly shown generally at 400, which is not compact. Thisassembly has a higher total package height because the known cantileverstructure is connected outside of the housing. In particular, a firstcantilever arm 402 is connected outside of a housing 404 to a pivotshaft 406 end 408 that extends downward to the outside of the housing404, which arrangement increases the overall height of the assembly. Theincreased height is at least about twice that of the present invention.The assembly 400 is particularly suited for larger motor vehicles suchas pickup trucks.

A first bushing 410 and a second bushing 412 are coupled to the pivotshaft 406 inside of the housing 404. Thus, the cantilever arm 402 islocated outside of the housing 404 and additionally is not locatedbetween the first and second bushings 410,412. To avoid high internalforce due to this arrangement, the housing 404 must be larger in size,which also adds material and weight.

By way of example, with a 1000 N directional force applied to the pivotshaft 406 where the cantilever arm 402 is connected, a 1500 N reactionforce is applied to the first bushing 410 and a 500 N reaction force isapplied to the second bushing 412. Thus, the force applied to the firstbushing 410 is at least about 3× higher than in the present inventiveexample set forth above and about 3× higher than the force applied tothe second bushing 412. In addition, the total pivot shaft 406 height isat least about twice as long as the present invention.

A second cantilever arm 414 is connected to a pivot shaft end extendingoutside of a hub structure 416 as well. Both the first and secondcantilever arms 402,414 are connected to a running board 418. Thehousing 404 includes a mounting bracket 420 and the hub structure 416includes a mounting bracket 422 arranged vertically in the vehicleinstalled position for mounting to the frame of a motor vehicle with aplurality of fasteners.

The power running board assembly generally 400 has longer cantileverarms 402,414 and running board 416 length as well. All theaforementioned factors make the known larger, heavier assembly moresuitable for larger motor vehicles.

Referring to now to FIGS. 15-18 and 21 generally, a running boardassembly, generally shown at 10, in one embodiment includes a runningboard 12, a housing assembly 14, a drive arm 16, an idler arm 18, alinear actuator assembly 20, a motor assembly 22, an electronic controlunit 24, and at least one mounting bracket 26. The mounting bracket 26is adapted for attachment to a frame of a motor vehicle 28.

The running board 12 has a top wall 30 providing a tread surface 32therealong. The running board 12 is connected to the drive 16 and idler18 arms at pivots generally shown at 34. The pivots 34 are arrangedgenerally vertically in vehicle installed position and include a shaftextending through a bore in the end of the drive 16 and idler 18 armsand retained in place by a retaining ring. The idler arm 18 is mountedto a hub structure 36 which pivotally secures the idler arm 18 to a rearbracket 38. The rear bracket 38 is mounted to the mounting bracket 26which is attached to the frame of the motor vehicle 28. It isappreciated that although a single idler arm 18 is shown, the runningboard assembly 10 in another embodiment may include more than one idlerarm 18.

The drive 16 and idler 18 arms form a parallel linkage which pivotallycouples the running board 12 to a frame of the motor vehicle 28 formovement between a stowed position, as shown in FIG. 16, a cab entryposition, as shown in FIG. 17, and a box side step position, as shown inFIG. 18. In the stowed position, the running board 12 is generallytucked underneath the motor vehicle 28 so as to be somewhat hidden fromview and to provide a cleaner, more integrated look to the motor vehicle28. In the cab entry position, the running board 12 extends generallyoutwardly from the motor vehicle 28 to assist users entering or exitinga passenger cab generally indicated at 40. And in the box side stepposition, the running board 12 extends generally outwardly from themotor vehicle 28 and is disposed rearward as compared to the cab entryposition in order to allow users side access to a box 41 of the motorvehicle 28. The running board 12 provides a more useful step surfacewith improved step length for box access as compared to a separate framemounted side step.

Referring to FIGS. 19 and 20, the housing assembly 14 includes a coverstructure 42 and a main housing structure 44. The cover structure 42 issecured to the main housing structure 44 by a plurality of coverfasteners 46, e.g., cover screws. The cover structure 42 and the mainhousing structure 44 define an internal chamber within the housingassembly 14. The housing assembly 14 also includes a steel tube portion48, a rear bracket 50, and a bracket 51 integrally formed with the coverstructure 42 and having an aperture for receiving a fastener 53, e.g.,nut and bolt arrangement, for securing to the rear bracket 50. Anotherbearing 67, e.g., spherical bearing with nitrile seals, is coupled tothe bracket 51. The rear bracket 50 of the housing assembly 14 issecured to the mounting bracket 26 adapted for attachment to the frameof the motor vehicle 28.

The linear actuator assembly 20 includes a ball screw member 52 disposedwithin the steel tube portion 48 and rotatable relative thereto. Theball screw member 52 is operably coupled to the motor assembly 22. Aworm member 54, e.g., plastic worm gear, is fixedly mounted toward anend of the ball screw member 52 for rotation therewith, and includes alead worm self locking member, generally shown at 55, e.g., worm gearwith self locking 4 degree lead angle. The worm member 54 can be of anysuitable configuration. A plurality of tapered roller bearings 56, e.g.,at least two, are mounted on an exterior surface of the worm member 54and/or ball screw member 52. The linear actuator assembly 20 alsoincludes an actuator shaft tube 58 with a tube insert 60 at one endoperably coupled to a spherical bearing 62, e.g., a spherical bearinghaving a PTFE liner (polytetrafluoroethylene) fitted therein and fixedlysecured to the bearing 62, preferably, spherical ball bearing havingstainless steel ball, PTFE liner and nitrile seals. At the other end ofthe actuator shaft tube 58 there is provide a bearing 64, preferably, asteel/PTFE sleeve bearing, and a ball nut 66 with internal ball returnfor linear movement thereof. Other suitable ball returns arecontemplated without departing from the scope of the invention. The ballscrew 52 and ball nut 66 have matching helical grooves. Bellows 65 areoperably fitted over at least the actuator shaft tube 58, ball nut 66,and bearing 64, operable for providing an environmental seal.

Ball screws are the method of choice in linear-actuation applications inaccordance with the present invention. Ball screws convert rotary inputto linear motion and offer several advantages over other actuators, suchas Acme screws, hydraulic or pneumatic systems, and belt, cable, orchain drives. Thus, the rotation of the ball screw 52 drives pivotalmovement of the drive arm 16. It is appreciated that other suitableactuators such as, but not limited to, air cylinder/pneumatic orhydraulic cylinder type, or other suitable linear motion screws arecontemplated without departing from the scope of the invention. By wayof non-limiting example, in one embodiment the actuator has a linearactuator gear drive arrangement or the linear actuator assembly has alinear actuator belt drive arrangement, in accordance with anotherembodiment of the present invention.

It is appreciated that in one embodiment a plurality of threads may bedefined on an exterior surface of the ball screw 52, in combination withoperational contact with the ball nut 66 internal ball returnarrangement and/or bearing 64.

Referring to FIGS. 15 and 19 generally, the drive arm 16 includes afirst end 68 rotatably coupled to the spherical bearing 62 and anopposing second end 70 rotatably coupled to a second mounting bracket 73fixedly connected to the running board 12. The drive arm 16 includes afirst link 72 pivotably connected to a second link 74 at a joint 75. Therotation of the ball screw 52 drives rotation of the first link 72 andpivotal movement about the joint 75 of the second link 74 to moverelative to the first link 72 causing the running board 12 to deploybetween stowed and a deployed positions. The joint 75 is mounted toanother hub structure 36 which pivotally secures the drive arm 16 to asecond rear bracket 38. This rear bracket 38 is mounted to the mountingbracket 26 which is attached to the frame of the motor vehicle 28.

Referring to FIGS. 15 and 19 through 21 generally, the motor assembly 22includes a casing structure 76 which includes a position sensing andencoding motor 78 that rotates a shaft in opposing first and seconddirections. The motor assembly 22 is secured to the linear actuatorassembly 20. More particularly, the shaft extends into the main housingstructure 44 and is fixedly secured to the worm gear 54 coupled with thelead worm self locking member 55 such that activation of the motor 78will rotate the self locking member 55 in the same direction causingrotation of the worm gear 54 which will cause rotation of the ball screwmember 52. The casing structure 76 is secured to the main housingstructure 44 by a second plurality of fasteners. It is appreciated thatthe casing structure 76 may in one embodiment be considered part of thehousing assembly 12 as the housing assembly 12 maintains the worm gearand motor components sealed from the external environment.

The electronic control unit 24 electronically controls the motorassembly 22 to effect movement of the running board 12 between thestowed, cab entry, and box side step positions. The electronic controlunit 24 is mounted within the motor vehicle 28 at a location remote fromthe housing assembly 14. The electronic control unit 24 is electricallyconnected to the motor assembly 22, to a wiring harness of the motorvehicle 28, and to a switch member 84 incorporated into a door 86 of themotor vehicle 28. In another embodiment, the electronic control unit 24may be physically mounted to the housing assembly 14 or to the motorassembly 22, and electronically connected to the motor assembly 22.

The switch member 84 in one embodiment is a door-actuated switch memberthat is part of the motor vehicle 28 and is controlled in a conventionalmanner by the door 86. The wiring harness supplies the electrical powerfrom the vehicle electrical system to the electronic control unit 24 ofthe running board assembly 10 through electrical wire members 88. Thestructure and operation of a conventional switch member which isoperationally interconnected to the vehicle door 86 is well known. It isunderstood by one skilled in the art that such switch members aretoggled by the opening or the closing of the vehicle door 86 associatedtherewith to open and close an electrical circuit. Wire members 90provide electrical connection between the electronic control unit 24 andthe motor assembly 22 so that the electronic control unit 24 can supplyelectrical power from the vehicle electrical system to the motorassembly 22 to effect the bi-directional operation thereof. Wire members92 provide electrical communication between the electronic control unit24 and the door-actuated switch member 84.

In one embodiment, the switch member 84 is a door ajar switch in a doorlatch. The motor assembly 22 is energized to move the running board 12from the stowed position to the cab entry position upon receiving asignal from the door ajar switch indicating that the vehicle door 86 hasbeen opened. The motor assembly 22 is energized to return the runningboard 12 to the stowed position upon receiving a signal from the doorajar switch indicating that the vehicle door 86 has been closed.

The running board assembly 10 has at least one stop that is internal tothe actuator and/or are external stops. It is appreciated that in oneembodiment there are no external stops.

In operation, starting with the running board 12 in the stowed position,when the vehicle door 86 is unlatched and pivoted outwardly from aclosed position to an open position, the switch member 84 associatedwith the vehicle door 86 is activated and sends a control signal to theelectronic control unit 24. The electronic control unit 24 in responseto the control signal supplies an appropriate voltage to the motorassembly 22 to cause the motor assembly 22 to begin rotational movementin a first rotational direction which will operably cause rotation ofthe ball screw member 52 to convert rotary input to linear motionthereof, thereby causing pivoting of the first link 72 relative to thesecond link 74 about joint 75 to move the running board 12 to the cabentry position. Specifically, the motor 78 rotates the lead worm 55causing rotation of the worm gear 54 in a first rotational directionwhich in turn rotates the ball screw member 52. The actuator shaft tube58 is rotatable with the ball screw member 52 and causes the drive arm16 to pivot outwardly away from the motor vehicle 28 to move the runningboard 12 to the cab entry position. The particular location of therunning board 12 in the cab entry position is electronically controlledby the motor 78. The electronic control unit 24 is programmed to stopthe motor 78 after a predetermined number of armature revolution counts.As a result, the exact location of the running board 12 in the cab entryposition may vary depending upon when the motor 78 is programmed tostop. When the electronic control unit 24 senses that the running board12 has reached the cab entry position, the electronic control unit 24turns off the motor 78.

The running board 12 is retained in the cab entry position after themotor assembly 22 is shut off as a result of at least the engagementbetween the worm gear 54 and the ball screw member 52, as it is knownthat the worm gear 54 will not be back-driven by the screw member 52.Specifically, the lead worm 55 is self locking and will not beback-driven. Thus, the lead worm 55 and/or worm gear 54 will resist anexternal force applied to the drive arm 16 in a direction away from thecab entry position and towards the stowed position as a result of theengagement.

The running board 12 remains in the cab entry position until the door 86of the motor vehicle 28 is returned to the closed position. When thedoor 86 is pivoted inwardly from the open position to the closedposition, the switch member 84 associated therewith is activated andsends a signal to the electronic control unit 24. The electronic controlunit 24 in response to the signal supplies an appropriate voltage to themotor assembly 22 which will pivot the drive arm 16 to move the runningboard 12 to the stowed position. Specifically, the shaft of the motorassembly 22 rotates the lead worm 55 causing rotation of the worm gear54 in a second rotational direction which in turn rotates the ball screwmember 52. The actuator shaft tube 58 is rotatable with the ball screwmember 52 and causes the drive arm 16 to pivot inwardly towards themotor vehicle 28 to move the running board 12 to the stowed position.

It is appreciated that in one embodiment at least two stops are locatedon each drive arm 16 and idler arm 18 to abut the running board 12. Thedrive arm 16 includes a stow stop 82 and end stop 80 formed at alocation between the joint 75 and second end 70. The running board 12abuts the stow stop 82 to stop further movement of the running board 12when the board 12 has reached the stowed position. The running boardabuts the end stop 80 when the board 12 has reached the box side stepposition to stop further movement of the running board 12. In oneembodiment, the stow and end stops 82, 80 include bumpers 81 formed fromurethane or a other suitable material. The stow stop 82 and electroniccontrol unit 24 are used to turn off the motor 78 of the motor assembly22. The running board 12 will continue to move towards the stowedposition until the running board abuts the stow stop 82. A current spikeis generated in the motor assembly 22 as a result of the motor assembly22 meeting a resistance to movement when the running board 12 hits thestow stop 82. The current spike will be instantaneously detected by theelectronic control unit 24. In response to the current spike, theelectronic control unit 24 turns off the motor 78. Likewise, the runningboard 12 will continue to move towards the box side step position untilthe running board abuts the end stop 80. A current spike is generated inthe motor assembly 22 as a result of the motor assembly 22 meeting aresistance to movement when the running board 12 hits the end stop 80.The current spike will be instantaneously detected by the electroniccontrol unit 24. In response to the current spike, the electroniccontrol unit 24 turns off the motor 78.

Referring to FIG. 22, the motor vehicle 28 may include an input membersuch as a body-mounted switch 96, an end cap switch 98, or a key fob toinitiate movement of the running board 12 into and out of the box sidestep position. The body-mounted switch 96 and the end cap switch 98 maybe electrically connected to the electronic control unit 24 by wiremembers 100 or by a wireless connection. The body-mounted switch 96 iseasily accessible by hand and the end cap switch 98 may be accessed by auser's foot. Thus, the running board 12 may be hand-operated, orfoot-operated if hands-free operation of the running board 12 isdesired. The running board 12 may be moved into the box side stepposition from either the stowed position or the cab entry position. Uponactivation of one of the switches 96, 98 or the key fob, a signal issent to the electronic control unit 24. The electronic control unit 24in response to the signal supplies an appropriate voltage to the motorassembly 22 to cause rotational movement in a first direction which willconvert rotary input to linear motion and pivot the drive arm 16linkages to move the running board 12 to the box side step position.

To move the running board 12 out of the box side step position and intothe stowed position, the body-mounted switch 96, the end cap switch 98,or the key fob is activated which sends a signal to the electroniccontrol unit 24. The electronic control unit 24 in response to thesignal supplies an appropriate voltage to the motor assembly 22 to causerotational movement in a second rotational direction which will convertrotary input to linear motion and pivot the drive arm 16 linkages tomove the running board 12 to the to the stowed position. Specifically,the motor shaft of the motor assembly 22 rotates the lead worm 55causing rotation of the worm gear 54 in a second rotational directionwhich in turn rotates the ball screw member 52. The actuator shaft tube58 rotates with the ball screw member 52 and causes the drive arm 16 topivot inwardly towards the motor vehicle 28 to move the running board 12to the stowed position. The running board 12 reaches the stowed positionwhen the running board 12 abuts the stow stop 82 on the drive arm 16. Acurrent spike is generated in the motor assembly 22 as a result of themotor assembly 22 meeting a resistance to movement when the runningboard 12 hits the stow stop 82. The current spike will beinstantaneously detected by the electronic control unit 24. In responseto the current spike, the electronic control unit 24 turns off the motor78. It is further contemplated that in the alternative the running board12 may be moved from the box side step position to the cab entryposition. It is appreciated that in one embodiment the stops for linearactuation are internal without any external stops.

Alternatively, a belt drive, spur gear drive, planetary geararrangement, or direct drive between armature and lead screw, or anyother predetermined arrangement adapted to and suitable fordeploying/stowing the running board from any predetermined vehiclesdepending on the applications.

Alternatively, the running board is movable relative to the housingassembly between a stowed position tucked underneath the motor vehicleand a motor vehicle compartment entry position generally outwardly fromthe motor vehicle to support a user entering or exiting the passengercab. Alternatively, the running board is movable relative to the housingassembly between a stowed position tucked underneath the motor vehicleand a plurality of deployed positions. Alternatively, the running boardis movable relative to the housing assembly between one stowed positionand one deployed position. Alternatively, the running board is movablerelative to the housing assembly between at least one stowed positionand at least one deployed position.

Referring now to FIGS. 23-25 generally, where like numbers denote likeparts, a power running board assembly, generally shown at 500, inanother embodiment includes a running board 512, a housing assemblyshown generally at 514, at least one first swing arm 518, at least onesecond swing arm 116, a linear actuator assembly shown generally at 520,a motor assembly shown generally 522, an electronic control unit 524,and at least two mounting brackets 526,528. The mounting brackets526,528 are adapted for attachment to a frame of a motor vehicle 540 orother predetermined vehicle structure. The at least two swing arms518,516 are pivotally connected to the running board 512 and pivotallyconnected to respective hub structures 538,538, forming a linkage. Thelinear actuator assembly 520 is connected to the running board 512toward one end of the linear actuator assembly 520. The linear actuatorassembly 520 is connected toward the other end to the motor vehiclebody, e.g. frame 540. The motor 522 actuates the linear actuatorassembly and drives movement of the linear actuator assembly 520, whichcauses movement of the linear actuator assembly 520 and drives the atleast two swing arms 518,516 to pivotally move the running board 512between the stowed position and any predetermined deployed position(s).Referring more particularly to FIG. 23, the actuator 520 is connected tothe step 512 instead of one of the swing arms 518,516.

In one embodiment, the drive arrangement includes a motor armature shaftand lead screw with a worm gear drive. Alternatively, a belt drive, spurgear drive, planetary gear arrangement, or direct drive between armatureand lead screw, or any other predetermined arrangement adapted to andsuitable for deploying/stowing the running board from any predeterminedvehicles depending on the applications.

Referring more particularly to FIG. 24, in one embodiment the actuatoris a linear actuator gear drive arrangement, indicated generally at 530,that includes a spur gear design with a plurality of in-meshed gears,shown generally at 532, and a motor assembly, shown generally at 534.The spur gear arrangement 532 is operably positioned between a motorarmature shaft, shown generally at 536, and a lead screw, showngenerally at 538, e.g., operable to convert rotary movement into linearmovement, to drive the running board 512 between predeterminedpositions.

Referring more particularly to FIG. 25, in one embodiment the linearactuator assembly has a linear actuator belt drive arrangement,indicated generally at 540, that includes a belt drive design with abelt device, shown generally at 542, and a motor assembly, showngenerally at 544. The belt drive arrangement 542 is operably positionedbetween a motor armature shaft, shown generally at 546, and a leadscrew, shown generally at 548, e.g., operable to convert rotary movementinto linear movement, to drive the running board 512 betweenpredetermined positions.

The description of the invention is merely exemplary in nature and,thus, variations that do not depart from the gist of the invention areintended to be within the scope of the invention. Such variations arenot to be regarded as a departure from the spirit and scope of theinvention.

What is claimed is:
 1. A compact power running board assembly for amotor vehicle, comprising: an actuator assembly operably coupled to aswing arm; a running board operably connected to said swing arm; ahousing assembly including an opening; a pivot shaft located within saidhousing assembly, said swing arm extending through said opening of saidhousing assembly and operably connected to said pivot shaft; a pair ofbushing bearings coupled to said pivot shaft within said housingassembly; and a motor assembly operably coupled to said actuatorassembly for driving said actuator assembly to move said running boardbetween at least one stowed position and at least one deployed position.2. The compact power running board assembly of claim 1, wherein saidpair of bushing bearings comprises a first bushing bearing mounted tothe pivot shaft at a location below the swing arm attachment and asecond bushing bearing mounted to the pivot shaft mounted to the pivotshaft at a location above the swing arm attachment location.
 3. Thecompact power running board assembly of claim 2, further comprising athrust bearing coupled to the pivot shaft between said swing arm andsaid first bushing bearing.
 4. The compact power running board assemblyof claim 1, further comprising a gap in said housing assembly locatedbetween said swing arm and interior walls of said housing assembly. 5.The compact power running board assembly of claim 4, further comprisingat least one seal inside said housing assembly operably to preventmoisture that entered said gap from said opening to travel to otherareas within said housing assembly other than for allowing said moistureto exit back out through said opening.
 6. The compact power runningboard assembly of claim 4, wherein said at least one seal is an oil sealcoupled immediately adjacent to the outside of a thrust bearing that ismounted to said pivot shaft immediately adjacent to a bottom of saidswing arm.
 7. The compact power running board assembly of claim 4,wherein a second seal is operably coupled immediately adjacent to a topsurface of said swing arm.
 8. The compact power running board assemblyof claim 1, further comprising a mechanical stop connected to said swingarm including at least two stop members, wherein a first stop contactssaid running board when in said at least one deployed position toprevent further movement of said running board in a first direction anda second stop contacts said running board when in said stowed positionto prevent further movement of said running board in a second direction.9. The compact power running board assembly of claim 8, furthercomprising an over current sensor operably coupled to said motorassembly that detects current spikes caused by said running boardcontacting an obstruction or contact with said first or second stops,wherein the current spike causes an electronic control unit to turn saidmotor assembly off.
 10. The compact power running board assembly ofclaim 8, wherein said mechanical stop includes an L-shaped mountingbracket with a first half including a first bumper that contacts a rearsurface of said running board when in the deployed position and a secondhalf including a second bumper that contacts said rear surface of saidrunning board when in the stowed position.
 11. The compact power runningboard assembly of claim 1, further comprising a key member operablycoupled to the pivot shaft and keyed to the swing arm to cause saidswing arm to pivot with rotation of the pivot shaft operably driven bythe actuator assembly.
 12. The compact power running board assembly ofclaim 1, wherein said actuator assembly is a rotary actuator comprisinga worm gear operably coupled to said motor assembly and in operablemeshing engagement with a worm wheel including a hub, wherein said hubis keyed to said pivot shaft, and wherein said motor assemblyselectively drives rotation of said worm gear in a first or seconddirection which drives rotation of said worm wheel to rotate said pivotshaft to pivot said swing arm between said stowed and deployedpositions.
 13. The compact power running board assembly of claim 12,further comprising at least one O-ring mounted to said pivot shaftimmediately adjacent to said worm wheel to prevent moisture fromentering the worm gear.
 14. The compact power running board assembly ofclaim 1, wherein the actuator assembly is selected from the groupconsisting of rotary actuator, linear actuator, pneumatic actuator,hydraulic actuator, ball screw/nut linear actuator, gear driven linearactuator, and belt driven linear actuator.
 15. The compact power runningboard assembly of claim 1, wherein said housing assembly furthercomprises an inboard mounting bracket member and an outboard mountingbracket member for attaching to said motor vehicle.
 16. The compactpower running board assembly of claim 1, further comprising an idlerswing arm mechanism including a second swing arm connected to saidrunning board and connected inside of an idler housing assembly, whereinsaid swing arm and said second swing arm form a parallel linkage to movesaid running board between said at least one stowed position and said atleast one deployed position when said swing arm is driven to rotate bysaid actuator assembly.
 17. The compact power running board assembly ofclaim 16, wherein said idler swing arm mechanism further includes apivot shaft located within said idler housing assembly, said secondswing arm extending through an opening of said idler housing assemblyand operably connected to said pivot shaft.
 18. The compact powerrunning board assembly of claim 17, wherein said idler swing armmechanism further includes a first bushing bearing mounted to said pivotshaft at a location below said second swing arm within said idlerhousing and a second bushing bearing mounted to said pivot shaft at alocation above said second swing arm within said idler housing.
 19. Thecompact power running board assembly of claim 16, wherein said idlerswing arm mechanism further includes at least two thrust bearingsmounted to said pivot shaft, one on each side of said second swing arm,to transfer force to said first and second bushing bearings.
 20. Thecompact power running board assembly of claim 19, further comprising atleast two oil seals mounted on the outside of said at least two thrustbearings, respectively, to seal against moisture within the idlerhousing assembly.
 21. The compact power running board assembly of claim16, wherein said idler housing assembly further comprises an inboardmounting bracket member and an outboard mounting bracket member forattaching to said motor vehicle.
 22. A compact power running boardassembly for a motor vehicle, comprising: an actuator assembly operablycoupled to a swing arm of a parallel linkage; a running board operablyconnected to said swing arm; a housing assembly including an opening; apivot shaft within said housing assembly, said swing arm extendingthrough said opening of said housing assembly and operably mounted tosaid pivot shaft; a motor assembly operably coupled to said actuatorassembly for driving said actuator assembly to move said running boardbetween at least one stowed position and at least one deployed position;a first bushing bearing coupled to said pivot shaft within said housingassembly at a location below said swing arm; and a second bushingbearing coupled to said pivot shaft within said housing assembly at alocation above said swing arm; wherein said swing arm located betweenand a predetermined distance from said first and second bushings withinsaid housing assembly provides a compact arrangement and reduces andbalances reaction forces of said first and second bearing bushingsapplied to said pivot shaft by directional force from said swing arm.23. The compact power running board assembly of claim 22, wherein saidactuator assembly comprises a worm gear operably coupled to beselectively driven by said motor assembly and in operable meshingengagement with a worm wheel, wherein said worm wheel is operablyconnected to said pivot shaft, and wherein said motor assemblyselectively drives rotation of said worm gear in a first or seconddirection which drives rotation of said worm wheel to rotate said pivotshaft to pivot said swing arm, and therefore said parallel linkage,between said at least one stowed position and said at least one deployedposition.
 24. A compact power running board assembly for a sport utilityvehicle, comprising: an actuator assembly operably coupled to a swingarm of a linkage; a running board operably connected to said linkage; ahousing assembly including an opening; a pivot shaft within said housingassembly, said swing arm extending through said opening of said housingassembly and operably mounted to said pivot shaft; a motor assemblyoperably coupled to said actuator assembly for driving said actuatorassembly to move said running board between at least one stowed positionand at least one deployed position; a first bushing bearing coupled tosaid pivot shaft within said housing assembly at a location below saidswing arm; and a second bushing bearing coupled to said pivot shaftwithin said housing assembly at a location above said swing arm; atleast one thrust bearing immediately adjacent to said swing arm totransfer force from said swing arm to said first bushing bearing;wherein said swing arm located between and a predetermined distance fromsaid first and second bushings within said housing assembly provides acompact arrangement and reduces reaction forces within the housingassembly by at least half.